Mexico’s Senate ended its summer recess on 27 August with an unprecedented fist-fight after opposition leader Alejandro “Alito” Moreno climbed the rostrum and grabbed chamber president Gerardo Fernández Noroña while legislators were still singing the national anthem. Television images from the congressional channel show Moreno pushing and swinging at the Morena senator, knocking over Noroña’s aide Emiliano González and damaging his camera equipment before security staff separated the lawmakers. Fernández Noroña, who was presiding over the last meeting of the Permanent Commission in the historic Xicoténcatl building, said the confrontation began because he had closed the session without allowing the PRI leader a final speech. He accused Moreno and three other PRI legislators—Pablo Angulo, Carlos Gutiérrez Mancilla and Eruviel Alonso—of a “premeditated” attack that left González with injuries requiring medical attention. Late Wednesday night agents of the federal prosecutor’s office (FGR) took statements from Fernández Noroña and his aide inside the Senate. The senator announced he will file criminal complaints for assault and property damage and will ask the chamber to lift the parliamentary immunity of Moreno and the other PRI participants at an extraordinary session he intends to convene on Friday. Moreno rejected the accusation, insisting that Fernández Noroña delivered the first shove after reneging on an agreement to grant him the floor, and said his party will mobilize supporters in response. The melee deepens tensions between the ruling coalition and the PRI as lawmakers prepare to reconvene for the regular session on 1 September.